docs: def view_contents(token, dstore):
      """
      Returns the size of the contents of the datastore and its total size
      """
      try:
          desc = dstore['oqparam'].description
      except KeyError:
          desc = ''
      data = sorted((dstore.getsize(key), key) for key in dstore)
      rows = [(key, humansize(nbytes)) for nbytes, key in data]
      total = '\n%s : %s' % (
          dstore.filename, humansize(os.path.getsize(dstore.filename)))
      return rst_table(rows, header=(desc, '')) + total